1. Field of the Invention
The present invention relates to sealing devices, and more particularly, to sealing devices for use with fluidly coupled parts in high temperature environments such as those found in gas turbine engines.
2. Description of Related Art
Assemblies such as fuel injectors which utilize fluidly coupled components in high temperature environments often require delivery of the fuel from an inlet fitting, where the fuel is relatively cool, through a feed arm, to an injector tip, where the fuel is combined with hot combustion air. As a result, the assemblies experience significant temperature variation between the inlet fitting and the injector tip. Temperature variation also occurs at particular locations in the assembly as the engine is operated at startup and at full power. These and other causes of temperature variation result in thermal expansion and contraction of assembly parts, which can lead to seal failures. For example, the growth differential of one or more parts caused by a hot feed arm and a cool fuel delivery tube can be exacerbated by the relatively long distances over which the fuel is transported.
Various methods have been utilized to accommodate growth differentials of assembly components, including, for example, coiling the fuel tube, utilizing O-rings and incorporating stretchable bellows. The drawbacks of these methods include the limited amount of assembly space typically available, the limited durability of the seals at high temperatures, their lack of serviceability, the long lead times for obtaining them, and high cost.
Such conventional methods and systems have generally been considered satisfactory for their intended purpose. However, there is still a need in the art for improved sealing capability with seals that are easily manufactured, assembled, and replaced, and which function with increased longevity.